Focusing device for signal lamps



April 24, 1928.

G. ROLFES VFOCUSING DEVICE FOR SIGNAL LAMPS Filed June 19. 1926 Patented Apr. 24, 1928.

GEORGE n. seams,

HANDLAN, on ST. Louis, mssoem v or sir. toms; msseu'ai; assies'oa to PATENT orrlcs.

ALEXANDER H.

i roeusme DEVICE FOR SIGNAL'LAMP'S;

Application filed June 19, 1926. SerSaLNo. 117,043..

My invention relates to a focusing device for properly adjusting in focal position an incai'ulescent bulb of a signal lampofthe type generallyemployed by railroads. The invention has for its object to provide ,asimple and highly eflicient device whereby a universal adjustment may be had within: a greatly circumscribed area.

In signal lamps in order to place the incandescent bulb in proper focal position said bulb is mounted immediately adjacent the reflector, and any movement of said bulb toward said reflector is necessarily limited by its proximity to said reflector. By my improved device I secure a maximum adjustment of the bulb mounting in all directions with a minimum de ree of movement of said mounting. It is understood that this adjustment primarily takes place before thesignal lamps are placed in service, and after such adjustment has been secured it is ordinarily unnecessary to change such adjustment.

\Vith the foregoing and other objects in view, the invention comprises the novel construction, combination and arrangement of parts hereinafter more specifically described and illustrated in the accompanying drawings, wherein is shown the preferred embodiment of the invention. However, it is to be understood that the invention comprehends changes, variations and modifications which come within the scope of the claims hereunto appended.

Fig. I is aside elevation, partly in section,

' of my'improved device in front of a reflector.

Fig. 11 is an enlarged sectional View of my improved device taken on line II-II in Fig. I.

Fig. III is a top plan View of my improved device.

In the drawing A designates a railroad signal lamp reflector. block to which is secured a base 2 as by screws 3. This base 2 is centrally apertured as at 4 to house a compression spring 5, the lower end of which spring seats upon a block 6,

preferably formed of bakelite or fiber. The

base 2 is also provided with three screwthreaded apertures as at 7 at its upper side to receive three screws 8, 9 and 10, which will be hereinafter referred to.

11 designates a socket of the bayonet type, and 12 is an incandescent bulb adapted to be 1 designates a base inserted insaid socket. 13 is an electrical contact, plug in the socket 11,, and14 is a metal contact member which leads from-one of the terminals 15 to conduct the electric current to the contact plug 13 and the bulb 12. .16 is another metal contact member leading from the other terminal 1 7- to the clamping sleeve '18 of the socket 11. The clamping sleeve 18 is provided with a plurality of expansible jaws 20, adjustment of which is controlled by means of a screw 19. By means of such a provision the lamp socket 11 may be adjusted vertically through the clamping sleeve 18, and it is to be observed that, owing to the fact that the sleeve 18 is offset from the base 2 of the device, the socket 11 may be adjusted without abutting against any of the other parts of the device.

21 designates a plate, preferably of bakelite (or fiber), upon which the socket 11 is mounted by means of the bracket arm 22 and screw 23. loosely through holes in the plate 21. The upper end of the spring 5 rests against the underside of the plate 21.

24 is a screw for securing the base block 1 to a member 25 upon which said base block is mounted. 26 designates. adjusting screws which are adapted to contact with the upper surface of the member 25 so that if there are any irregularities in said surface the same may be compensated for by the adjusting screws 26.

In the operation of my device the parts are assembled as illustrated in Figs. II and III, the plate 21 resting upon and supported. solely by the upper end of the spring 5. The screws 8, 9 and 10 are relatively long, and as already described, their lower portions are positioned in screw-threaded holes in the base 2. The vertical focal position of the bulb 12 is first obtained by'raising or lowering the plate 21 by the screws 8, 9 and 10, after which the lateral focal position is obtained by screwing in or out one or the other of the several screws 8, 9 or 10. hen these focal positions have been obtained the signal lamp is then ready for service with bulbs, selected for the accuracy of their filament placement with respect to the sleeve thereof, without the necessity of further focal adj ustment of the lamp. By this arrangement, it may be observed, I can obtain a wide range of lateral focal adjustment with a relatively small amount of movement of the mounting of the bulb 12.

I claim: I

1. A device for use in focusing a lamp relatively to a reflector comprising a hollow base member, a compression spring located within said base, an adjustable lamp-carrying plate located above the hollow base and normally urged upwardly by means of said compression spring, and a. plurality of fastenings spaced about the compression spring and extending from said adjustable plate to the hollow base, said fastenings being independently adjustable to tilt the lampcarrying plate relatively to the reflector.

2. A device for use in focusing a lamp relatively to a reflector comprising in combination a hollow base, a compression spring positioned within the hollow formed in the base, an adjustable plate located above the hollow base, headed members extending through the adjustable plate and engaging within the hollow b-aseein such a manner that the heads of the members limit upward movement that is imparted to the adjustable plate by means of the compression spring, a sleeve carried by the adjustable plate, and a lamp socket mounted within the sleeve, the sleeve: comprising an expansible collar oflset laterally from the adjustable plate and hollow base to permit free vertical adjustment of the socket relatively to the sleeve.

In testimony that I claim the foregoing I hereunto afiix my signature.

' GEORGE H. ROLFES. 

